[PATCH v2 1/5] src/t_dir_offset2: Add an option to limit of buffer size

Amir Goldstein
2021-04-25T07:14:52Z

Will be used to force readdir in several getdents calls.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
src/t_dir_offset2.c | 26 +++++++++++++++++++++-----
1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/src/t_dir_offset2.c b/src/t_dir_offset2.c
index 5a6d7193..7aeb990e 100644
--- a/src/t_dir_offset2.c
+++ b/src/t_dir_offset2.c
@@ -30,16 +30,32 @@ struct linux_dirent64 {
static uint64_t d_off_history[HISTORY_LEN];
static uint64_t d_ino_history[HISTORY_LEN];

-int
-main(int argc, char *argv[])
+void usage()
{
- int fd, nread;
+ fprintf(stderr, "usage: t_dir_offset2: [bufsize]\n");
+ exit(EXIT_FAILURE);
+}
+
+int main(int argc, char *argv[])
+{
+ int fd;
char buf[BUF_SIZE];
+ int nread, bufsize = BUF_SIZE;
struct linux_dirent64 *d;
int bpos, total, i;
off_t lret;
int retval = EXIT_SUCCESS;

+ if (argc > 2) {
+ bufsize = atoi(argv[2]);
+ if (!bufsize)
+ usage();
+ if (bufsize > BUF_SIZE)
+ bufsize = BUF_SIZE;
+ } else if (argc < 2) {
+ usage();
+ }
+
fd = open(argv[1], O_RDONLY | O_DIRECTORY);
if (fd < 0) {
perror("open");
@@ -48,7 +64,7 @@ main(int argc, char *argv[])

total = 0;
for ( ; ; ) {
- nread = syscall(SYS_getdents64, fd, buf, BUF_SIZE);
+ nread = syscall(SYS_getdents64, fd, buf, bufsize);
if (nread == -1) {
perror("getdents");
exit(EXIT_FAILURE);
@@ -89,7 +105,7 @@ main(int argc, char *argv[])
exit(EXIT_FAILURE);
}

- nread = syscall(SYS_getdents64, fd, buf, BUF_SIZE);
+ nread = syscall(SYS_getdents64, fd, buf, bufsize);
if (nread == -1) {
perror("getdents");
exit(EXIT_FAILURE);
--
2.31.1